Generic Movie dissolve (sand effect)
I found a solution (the best way is playing with all parameters). I think it is a good way to do what I want :-).

Step 1 :


Add a cube
Add a wind force field
Add a plane (for particles)


Step 2 : 


Subdivision Surface on the plane -> to have more Faces for particles.
Add ParticleSystem on the plane and just put the same Face number in Emission number.


Step 3 : 


Put the wind Force Field in the cube
Rotate (R|Y|90) the wind
Add Physics Collision on the cube

-> Set Force Fields Absorption : 1.00 (maximum)
Wind Force Field

-> In Physics : Collision -> Check Absorption
-> In Physics : Change the Strength to see the particle movement


When the plane are not in the cube, with gravity, they fall on Z axis. Create an animation on the cube (with Wind) or on the plane. When the plane are in the cube, particles fall on Z axis with a movment on the right.

Now I can create my text and animate all :-). 

Hope this solution is good and maybe can help someone else :-).